The invention relates to a luminaire having a reflector which mixes light from a multi-color array of LEDs, and more particularly to a low-profile luminaire which generates white light from a linear array of LEDs.
A standard low profile luminaire for mounting in a ceiling employs tubular discharge lamps having fluorescent coatings which determine the spectra of emitted light. The lamps generally are not dimmable, and the user has no control over the color temperature.
An array of LEDs in each of a plurality of colors offers the possibility of creating a luminaire in which the color temperature may be controlled at any power level, thereby enabling a lamp which is dimmable and emits a uniformly white light at any power level.
The English abstract of JP-A-06 237 017 discloses a polychromatic light emitting diode lamp having a 3.times.3 array of light emitting diodes of two types, a first type having elements for emitting red light and blue light, and a second type having elements for emitting red light and green light. The stated object is to mix colors so that the mixed color would be recognized as the same color in any direction, but there are no optical provisions to facilitate mixing. It is simply a two-dimensional array of LEDs in a lamp case filled with resin, which would do little more than provide some diffusion.
U.S. application Ser. No. 09/277,645, which was filed on Mar. 26, 1999, discloses a luminaire having a reflector which mixes light from a multi-color array LEDs. The array is arranged in the entrance aperture of a reflecting tube which preferably flares outward toward the exit aperture, like a horn, and has a square or other non-round cross section. The object is to produce a collimated beam of white light in the manner of a spotlight. However the design is unsuitable for a low-profile luminaire for general diffuse illumination.